80721471221 has 2 divisors, whose sum is σ = 80721471222. Its totient is φ = 80721471220.

The previous prime is 80721471179. The next prime is 80721471241. The reversal of 80721471221 is 12217412708.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57414868996 + 23306602225 = 239614^2 + 152665^2 .

It is a cyclic number.

It is not a de Polignac number, because 80721471221 - 2⁶ = 80721471157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80721471241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40360735610 + 40360735611.

It is an arithmetic number, because the mean of its divisors is an integer number (40360735611).

Almost surely, 2^80721471221 is an apocalyptic number.

It is an amenable number.

80721471221 is a deficient number, since it is larger than the sum of its proper divisors (1).

80721471221 is an equidigital number, since it uses as much as digits as its factorization.

80721471221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12544, while the sum is 35.

Adding to 80721471221 its reverse (12217412708), we get a palindrome (92938883929).

The spelling of 80721471221 in words is "eighty billion, seven hundred twenty-one million, four hundred seventy-one thousand, two hundred twenty-one".